Corkscrew



FIG. 1 is a side view of a corkscrew showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a back view thereof; and,

FIG. 5 is a top plan view thereof. 

The ornamental design for a corkscrew, as shown and described. 